1. Field of the Invention
The present invention relates to semiconductor packages and, more particularly, to a method for manufacturing semiconductor packages.
2. Discussion of Related Art
To fabricate a semiconductor package, a fabrication (FAB) process for forming integrated circuits on a wafer is performed. Thereafter, chips formed on the wafer are diced, each of the diced chips is bonded on a die bonding pad of a respective lead frame, and the bonding pads on the chips and inner leads of the lead frame are electrically connected with bonding wires. Next, the a molding step is performed for protecting the circuit.
After the step of molding, a support bar and a dam bar of the lead frame are trimmed and outer leads are formed in a predetermined form thereby completing the whole process of manufactoring the semiconductor package.
FIGS. 1A and 1D are cross-sectional views illustration steps of a conventional method for manufacturing a semiconductor package. As shown in FIG. 1A, a semiconductor chip 3 on which a bonding pad 2 is formed is die-bonded on a die bonding pad of the lead frame using an eutectic material 4 such as Au epoxy, AuSn, or AuSi. This die-boding is performed at a temperature of 200.degree. C.-300.degree. C. for 5 minutes-2 hours.
Subsequently, the bonding pad 2 formed on the surface of the semiconductor chip 3 is electrically connected to an inner lead 5 in the lead frame, as shown in FIG. 1B, by means of a wire 6 made of Ag or aluminum.
Next, as shown in FIG. 1C, all except an outer lead 8 are enveloped with an epoxy molding compound 7. Thereafter, as shown in FIG. 1D, the molded semiconductor package is cut from the lead frame and the outer lead 8 is formed in a desired form, thereby completing the semiconductor package.
However, the conventional method for manufacturing the semiconductor package has the following problems. First, since, it as long as takes 2 hours for the step of curing after die bonding, its production cost is high. Second, heat or ultrasonic waves are used for wire-bonding, so micro cracks may occur in the semiconductor chip. Third, since it takes so much time for wire-bonding and molding, the manufacturing process is inefficient and uneconomical.